Device for driving photographing lens and finder device of camera having zoom lens

ABSTRACT

A zoom lens camera having a zoom photographing lens and a zoom finder device are driven in association with each other so that the image plane and the finder field of view correspond to each other. A pair of pinions for the zoom photographing lens and the zoom finder device are provided in a gear train and are driven by a reversible motor so that the zoom photographing lens and the zoom finder device are driven by the respective pinions.

This application is a continuation, of application Ser. No. 08/015,074,filed Feb. 8,1993, now abandoned, which is a continuation of 07/750,266,filed Aug. 27, 1991, now abandoned, which is a continuation of07/414,123, filed Sep. 27, 1989, which issued as Pat. No. 5,068,678 onNov. 26, 1991.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device for driving a photographinglens and a finder device of a zoom lens camera having a photographinglens system and a finder optical system which are arranged separatelyfrom each other. The present invention further relates to a device foradjusting the assembly of the photographing lens and the finder device.

2Description of Related Art

In zoom lens cameras of the type having a photographing lens system anda finder optical system which are arranged separately from each other,it is common practice to make the image plane (focal length) of the zoomphotographing lens correspond to the finder field of view of the zoomfinder device. For this purpose, the movable lenses that constitute thezoom finder device are moved in association with the zooming operationof the photographing lens. However, the conventional connecting (orassociation) mechanisms are generally arranged such that the movement ofa cam ring for the photographing lens is transmitted to the movablelenses of the zoom finder device through interconnecting members such asa cam plate, and therefore the structure becomes complicated. It is alsotroublesome and difficult to adjust the assembly of the zoomphotographing lens and the zoom finder device so that these two deviceswill be effectively driven in association with each other.

SUMMARY OF THE INVENTION

In view of the above-described problems of the prior art, it is aprimary object of the present invention to provide a driving devicewhich is capable of driving the zoom photographing lens and the zoomfinder device in association with each other with a simplifiedstructure.

It is another object of the present invention to provide a drivingdevice which facilitates the adjustment of the relationship between thezoom photographing lens and the zoom finder device.

According to the present invention, the zoom photographing lens and thezoom finder device are driven without such an interlocked relationshipthat either one of the two is driven in response to the movement of theother.

For this purpose, the present invention employs a pair of pinions whichare provided in a gear train driven by a reversible motor to drive thezoom photographing lens and the zoom finder device, respectively.

The arrangement that the zoom photographing lens and the zoom finderdevice are individually driven simplifies the association mechanismbecoming complicated.

If a cam ring which effects zooming by rotation is provided on the zoomphotographing lens and a gear which meshes with the pinion for the zoomphotographing lens is provided on this cam ring, it is possible to drivethe zoom photographing lens by the rotation of the pinion.

If a finder cam member which changes the finder field of view isprovided on the zoom finder device and a gear which meshes with thepinion for the zoom finder device is provided on this finder cam member,it is possible to drive the zoom finder device through the rotation ofthe pinion. The finder cam member may be constituted by a cam ringsimilar to that for the photographing lens. It is also possible toconstitute the finder cam member by use of a finder cam plate which hasa vertical rack. More specifically, the arrangement may be such that avertical rack is formed on the finder cam plate and the pinion for thezoom finder device meshes with the rack.

If the gear which is meshes with the pinion for the zoom photographinglens and tile cam ring are secured in such a manner that the angularposition of the gear relative to the cam ring is adjustable, it ispossible to readily obtain synchronization between tile zoomphotographing lens and the zoom finder device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings show in combination one embodiment of thepresent invention, in which:

FIG. 1 is a perspective view illustrating main components of theembodiment with the zoom finder device removed;

FIG. 2 is a perspective view illustrating the general arrangement of theembodiment;

FIG. 3 is a plan view illustrating the zoom photographing lens and thezoom finder device; and

FIGS. 4 and 5 are front and plan views, respectively, illustrating theembodiment with the zoom finder device removed.

DETAILED DESCRIPTION

The present invention will be described below in detail by way of oneembodiment and with reference to the accompanying drawings. A zoomphotographing lens 11 has a cam ring 12 on the outer periphery thereof.The cam ring 12 is formed with zooming cam grooves 13 and 14 for movablelenses and a cam groove 15 for moving the strobe device. In the zoomingcam grooves 13 and 14 are fitted guide pins 16 and 17 which areintegrally provided on front and rear lens groups (not shown),respectively. The cam ring 12 has a sector gear 19 secured to the outerperiphery thereof through setscrews 18. The sector gear 19 hascircumferential slots (or elongated bores) 19a, so that the angularposition of the sector gear 19 relative to the cam ring 12 is adjustablewithin the range of the effective length of the slots 19a.

A zoom finder device 20 is disposed at one side of the zoomphotographing lens 11. The optical path of the zoom finder device 20 isbent in a crank-like shape in plan view in order to bring it as close tothe zoom photographing lens 11 as possible to thereby minimize theparallax and to ensure a space at the rear of the zoom photographinglens 11. More specifically, as shown in FIG. 3, the zoom finder device20 has an optical path 20A which is orthogonal to the optical axis ofthe photographing lens 11 and optical paths 20B and and 20C which extendfrom the two ends of path 20A in opposite directions and which areparallel to the optical axis of the photographing lens 11. Thus the zoomfinder device 20 has a crank-shaped planar configuration.

The optical system of the zoom finder device 20 comprises an objectivelens 21, a combination of movable lenses (variable power lenses) 22 (22aand 22b) which are movable together as a unit, a movable lens (variablepower lens) 23, reflecting mirrors 24, 25, a relay lens 26 and aneyepiece lens 27. Thus, an aerial image formed by the objective lens 21and the movable lenses 22 and 23 is observed after being changed to acorrect image through the reflecting mirrors 24, 25, the relay lens 26and the eyepiece lens 27. The reference numeral 28 denotes a fieldframe.

The movable lenses 22 and 23 are each moved along a predetermined trackto change the finder field of view. Driving pins 30 and 31 are providedon the respective supporting members (movable lens frames) for themovable lenses 22 and 23. The driving pins 30 and 31 extend through thecasing 32 of the zoom finder device 20 to fit in zooming cam grooves 34and 35, respectively, which are provided in a finder cam plate 33.

The finder cam plate 33 has at its rear end a rectangular portion 33awhich surrounds the bent portion 32a (i.e., the orthogonal optical path20A) of the casing 32, and a vertical rack 38 is formed on the rear endportion of the rectangular portion 33a.

A driving unit 40 is secured to the rear end of the bent portion 32a ofthe casing 32. The driving unit 40 is arranged such that the rotation ofa reversible motor 41 is transmitted to a pair of pinions 46 and 47through a worm 42, a worm wheel 43 and a gear train 44 which is in meshwith the worm wheel 43. The pinion 46 is in mesh with the sector gear 19on the cam ring 12, while the pinion 47 is in mesh with the rack 38 onthe Finder cam plate 33. As shown in FIGS. 4 and 5, a common first geartrain includes reversible motor 41 worm wheel 43 and gear train 44. Asecond gear train includes pinion 46 and sector gear 19. A third geartrain include pinion 47 and rack 38. The second and third gear trainsseparately engage the common first gear train and the second and thirdgear trains contain no common elements.

Accordingly, as the reversible motor 41 is driven forward or backward,the pinions 46 and 47 rotate simultaneously and the rotation of thepinion 46 causes the cam ring 12 to rotate through the sector gear 19.As the cam ring 12 rotates forward or backward, the front and rear lensgroups move along the optical axis by the action of the zooming camgrooves 13 and 14 while changing the distance (air gap) there between,thus effecting zooming of the zoom photographing lens.

Meanwhile, as the pinion 47 rotates forward or backward, the finder camplate 33 moves vertically and this causes the movable lenses 22 and 23to move along the optical axis by the zooming cam grooves 34 and 35,thus effecting zooming of the zoom finder device 20. By individuallydriving the zoom photographing lens 11 and the zoom finder device 20 inthis way, it is possible to obtain a driving device which needs nointerlocking member between the zoom photographing lens 11 and the zoomfinder device 20.

The zoom photographing lens 11 and the zoom finder device 20 areadjusted so that the image plane of the zoom photographing lens 11 issubstantially identical to the finder field of view of the zoom finderdevice 20. According to the present invention, the adjustment of theassembly of the zoom photographing lens 11 and the zoom finder device 20can be effected by adjusting the angular position of the sector gear 19relative to the cam ring 12 within the effective length of the slots19a; therefore, the adjusting operation is extremely easy. Morespecifically, after the driving unit 40, the zoom finder device 20 andthe zoom photographing lens 11 have been roughly assembled, thepositional relationship between the driving unit 40 and the zoom finderdevice 20 is first fixed and then the angular position of the sectorgear 19 relative to the cam ring 12 is determined while checking therelationship between the finder field of view (i.e., focal length) ofthe zoom finder device 20 and the size of the image plane (i.e., focallength) of the zoom photographing lens 11', thereafter the setscrews 18are tightened. By so doing, synchronization between the zoom finderdevice 20 and the zoom photographing lens 11 can be obtained with ease.

The camera of the illustrated embodiment further has a variableillumination angle strobe device 50 which is provided on that side ofthe zoom photographing lens 11 which is remote from the zoom finderdevice 20. The strobe device 50 is designed to vary the illuminationangle in association with the rotation of the cam ring 12. The strobedevice 50 has a xenon lamp (light emitting tube ) 51a and a reflectingshade 51b which constitute in combination a strobe moving block 51 and acondenser lens (Fresnel lens; see FIG. 2) 52. The strobe moving block 51is moved relative to the condenser lens 52 to thereby vary theillumination angle.

A guide bar 54 which extends parallel to the optical axis of the zoomphotographing lens 11 is fixed below one side of the lens 11. A relayblock 55 is movably supported on the guide bar 54. The relay block 55has a guide pin 55a which is fitted in the strobe moving cam groove 15provided in the cam ring 12, so that as the cam ring 12 rotates, therelay block 55 moves along the optical axis. The relay block 55 and thestrobe moving block 51 of the strobe device 50 are interlocked with eachother through an interlocking lever 56 which pivots about a pivot point56a. More specifically, two ends of the interlocking lever 56 areengaged with interlocking pins 59 and 60, respectively, which aresecured to the relay block 55 and the strobe moving block 51, so thatthe strobe moving block 51 moves along the optical axis through themovement of the relay block 55 along the optical axis caused by therotation of the cam ring 12 and the pivoting action of the interlockinglever 56. The profile of the strobe moving cam groove 15 and the lengthsof the arms of the interlocking lever 56 are determined so that thestrobe illumination angle that is determined by the position of thestrobe moving block 51 corresponds to the change in the focal length ofthe zoom photographing lens 11 caused by the rotation of the cam ring12.

As has been described above, according to the present invention the zoomphotographing lens and the zoom finder device are driven without aninterlocked relationship wherein either one of the two is driven inresponse to the movement of the other. Since the zoom photographing lensand the zoom finder device are driven by a pair of pinions,respectively, which are incorporated in a gear train driven by areversible motor, it is possible to obtain a lens shutter type camerahaving a zoom lens which operates effectively without complication ofthe associated relationship between the zoom photographing lens and thezoom finder device. If the pinion for the zoom photographing lens mesheswith a gear which is secured to the cam ring and this gear and the camring are secured together in such a manner that the angular position ofthe gear relative to the cam ring is adjustable, it Is possible toreadily obtain synchronization between the zoom photographing lens andthe zoom finder device.

We claim:
 1. A zoom lens camera having a zoom-photographing lens and azoom finder device which are driven in association with each other sothat the image plane and the finder field of view correspond to eachother, comprising:a common first gear train including a reversiblemotor, for driving both the zoom-photographing lens and the zoom finderdevice; a second gear train including a first pinion for the zoomphotographing lens; and a third gear train including a second pinion forthe zoom finder device; wherein each said second and third gear trainsseparately engage said common first gear train and said second and thirdgear trains contain no common elements.
 2. The zoom lens cameraaccording to claim 1, said third gear train further comprising a camelement for varying the finder field of view, said cam element providedwith a toothed member which is engaged with said second pinion.
 3. Thezoom lens camera according to claim 2, said toothed member comprising avertical rack which is engaged with said second pinion.
 4. The zoom lenscamera according to claim 1, said second gear train further comprising acam ring mounted for rotation, rotation of said cam ring effectingzooming of said photographing lens, said cam ring comprising a toothedsegment, the relative angular position of said cam ring and said toothedsegment being adjustable.
 5. The zoom lens camera according to claim 1,said third gear train further comprising a vertically movable finder camplate positioned at a side of a finder cam housing and a cam arrangementprovided on said cam plate for moving at least one lens of said zoomfinder device for zooming of said zoom finder device.
 6. A zoom lenscamera comprising:a translationally immobile drive member; azoom-photographing lens having an optical axis and a zoom finder devicewhich are driven in association with each other so that the image planeand the finder field of view correspond to each other, wherein a geartrain for the zoom-photographing lens and a gear train for the zoomfinder device are separately engaged with said translationally immobiledrive member and are disengageably engaged with said translationallyimmobile drive member to be driven by a driving force from a singledrive source through a common drive train, and said gear train for thezoom-photographing lens lacks any elements which are common with saidgear train for the zoom finder device.
 7. A zoom lens camera accordingto claim 6, wherein said gear train for the zoom-photographing lenscomprises a first pinion associated with said common drive train, andsaid second drive train comprises a second pinion associated with saidcommon drive train;wherein said common drive train comprises a motorwhich rotates said first and second pinions for driving the gear trainsfor the zoom photographing lens and the zoom finder device,respectively.
 8. A zoom lens camera according to claim 6, wherein saidzoom photographing lens gear train and said zoom finder device geartrain are driven in planes not parallel to the optical axis of the zoomphotographing lens.
 9. The zoom lens camera according to claim 6, saidgear train for said zoom-photographing lens and said gear train for thezoom finder device being directly driven from said translationallyimmobile drive member.
 10. A photographic camera having azoom-photographing lens and a zoom finder device which are driven inassociation with each other so that the image plane and the finder fieldof view correspond to each, means for driving said zoom-photographinglens and said zoom finder device, said driving means comprising a commondrive unit for driving a drive train for said photographing lens and fordriving a drive train for said zoom finder device, said drive train forsaid zoom-photographing lens and said drive train for said zoom finderdevice being separately drivingly coupled to said common drive unit, andsaid drive train for said photographing lens lacking any elements whichare common with elements of said drive train for said zoom finderdevice.
 11. The photographic camera according to claim 10, said drivetrain for said photographing lens comprising a pinion engaging saidcommon drive unit and said drive train for said zoom finder devicecomprising a pinion engaging said common drive unit.
 12. Thephotographic camera according to claim 11, said drive train for saidzoom finder device further comprising a cam element for varying thefinder field of view, said cam element provided with a toothed memberwhich is engaged with said pinion of said drive train for said zoomfinder device.
 13. The photographic camera according to claim 12, saidtoothed member comprising a vertical rack which is engaged with saidpinion of said drive train for said zoom finder device.
 14. Thephotographic camera according to claim 10, said zoom photographing lensdrive train comprising a cam ring mounted for rotation, rotation of saidcam ring comprising means for effecting zooming of said zoomphotographing lens, said cam ring comprising a toothed segment, therelative angular position of said cam ring and said toothed segmentbeing adjustable.
 15. The photographic camera according to claim 10,said zoom finder device drive train comprising a vertically movablefinder cam plate positioned at a side of a finder housing and a camarrangement provided on said cam plate for moving at least one lens ofsaid zoom finder device for zooming of said zoom finder device.
 16. Thephotographic camera according to claim 10, said drive train for saidphotographing lens comprising a pinion engaging said common drive unitand said drive train for said zoom finder device comprising a pinionengaging said common drive unit, each of said pinions being driven by areversible motor so that said zoom photographic lens and said zoomfinder device are driven by said respective pinions through said drivetrain for the zoom photographic lens and said drive train for the zoomfinder device, said drive train for the zoom photographic lens and saiddrive train for the zoom finder device being separate from one another.17. The photographic camera according to claim 10, said drive train forsaid zoom-photographing lens and said drive train for said zoom finderdevice being directly driven from said single drive unit.